xref: /openbmc/linux/drivers/pci/hotplug/acpiphp_core.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  * ACPI PCI Hot Plug Controller Driver
3  *
4  * Copyright (C) 1995,2001 Compaq Computer Corporation
5  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
6  * Copyright (C) 2001 IBM Corp.
7  * Copyright (C) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com)
8  * Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com)
9  * Copyright (C) 2002,2003 NEC Corporation
10  * Copyright (C) 2003-2005 Matthew Wilcox (matthew.wilcox@hp.com)
11  * Copyright (C) 2003-2005 Hewlett Packard
12  *
13  * All rights reserved.
14  *
15  * This program is free software; you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; either version 2 of the License, or (at
18  * your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful, but
21  * WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
23  * NON INFRINGEMENT.  See the GNU General Public License for more
24  * details.
25  *
26  * You should have received a copy of the GNU General Public License
27  * along with this program; if not, write to the Free Software
28  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29  *
30  * Send feedback to <kristen.c.accardi@intel.com>
31  *
32  */
33 
34 #include <linux/init.h>
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 
38 #include <linux/kernel.h>
39 #include <linux/pci.h>
40 #include <linux/pci_hotplug.h>
41 #include <linux/slab.h>
42 #include <linux/smp.h>
43 #include "acpiphp.h"
44 
45 #define MY_NAME	"acpiphp"
46 
47 /* name size which is used for entries in pcihpfs */
48 #define SLOT_NAME_SIZE  21              /* {_SUN} */
49 
50 static int debug;
51 int acpiphp_debug;
52 
53 /* local variables */
54 static int num_slots;
55 static struct acpiphp_attention_info *attention_info;
56 
57 #define DRIVER_VERSION	"0.5"
58 #define DRIVER_AUTHOR	"Greg Kroah-Hartman <gregkh@us.ibm.com>, Takayoshi Kochi <t-kochi@bq.jp.nec.com>, Matthew Wilcox <willy@hp.com>"
59 #define DRIVER_DESC	"ACPI Hot Plug PCI Controller Driver"
60 
61 MODULE_AUTHOR(DRIVER_AUTHOR);
62 MODULE_DESCRIPTION(DRIVER_DESC);
63 MODULE_LICENSE("GPL");
64 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
65 module_param(debug, bool, 0644);
66 
67 /* export the attention callback registration methods */
68 EXPORT_SYMBOL_GPL(acpiphp_register_attention);
69 EXPORT_SYMBOL_GPL(acpiphp_unregister_attention);
70 
71 static int enable_slot		(struct hotplug_slot *slot);
72 static int disable_slot		(struct hotplug_slot *slot);
73 static int set_attention_status (struct hotplug_slot *slot, u8 value);
74 static int get_power_status	(struct hotplug_slot *slot, u8 *value);
75 static int get_attention_status (struct hotplug_slot *slot, u8 *value);
76 static int get_latch_status	(struct hotplug_slot *slot, u8 *value);
77 static int get_adapter_status	(struct hotplug_slot *slot, u8 *value);
78 
79 static struct hotplug_slot_ops acpi_hotplug_slot_ops = {
80 	.owner			= THIS_MODULE,
81 	.enable_slot		= enable_slot,
82 	.disable_slot		= disable_slot,
83 	.set_attention_status	= set_attention_status,
84 	.get_power_status	= get_power_status,
85 	.get_attention_status	= get_attention_status,
86 	.get_latch_status	= get_latch_status,
87 	.get_adapter_status	= get_adapter_status,
88 };
89 
90 /**
91  * acpiphp_register_attention - set attention LED callback
92  * @info: must be completely filled with LED callbacks
93  *
94  * Description: This is used to register a hardware specific ACPI
95  * driver that manipulates the attention LED.  All the fields in
96  * info must be set.
97  */
98 int acpiphp_register_attention(struct acpiphp_attention_info *info)
99 {
100 	int retval = -EINVAL;
101 
102 	if (info && info->owner && info->set_attn &&
103 			info->get_attn && !attention_info) {
104 		retval = 0;
105 		attention_info = info;
106 	}
107 	return retval;
108 }
109 
110 
111 /**
112  * acpiphp_unregister_attention - unset attention LED callback
113  * @info: must match the pointer used to register
114  *
115  * Description: This is used to un-register a hardware specific acpi
116  * driver that manipulates the attention LED.  The pointer to the
117  * info struct must be the same as the one used to set it.
118  */
119 int acpiphp_unregister_attention(struct acpiphp_attention_info *info)
120 {
121 	int retval = -EINVAL;
122 
123 	if (info && attention_info == info) {
124 		attention_info = NULL;
125 		retval = 0;
126 	}
127 	return retval;
128 }
129 
130 
131 /**
132  * enable_slot - power on and enable a slot
133  * @hotplug_slot: slot to enable
134  *
135  * Actual tasks are done in acpiphp_enable_slot()
136  */
137 static int enable_slot(struct hotplug_slot *hotplug_slot)
138 {
139 	struct slot *slot = hotplug_slot->private;
140 
141 	dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));
142 
143 	/* enable the specified slot */
144 	return acpiphp_enable_slot(slot->acpi_slot);
145 }
146 
147 
148 /**
149  * disable_slot - disable and power off a slot
150  * @hotplug_slot: slot to disable
151  *
152  * Actual tasks are done in acpiphp_disable_slot()
153  */
154 static int disable_slot(struct hotplug_slot *hotplug_slot)
155 {
156 	struct slot *slot = hotplug_slot->private;
157 	int retval;
158 
159 	dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));
160 
161 	/* disable the specified slot */
162 	retval = acpiphp_disable_slot(slot->acpi_slot);
163 	if (!retval)
164 		retval = acpiphp_eject_slot(slot->acpi_slot);
165 	return retval;
166 }
167 
168 
169 /**
170  * set_attention_status - set attention LED
171  * @hotplug_slot: slot to set attention LED on
172  * @status: value to set attention LED to (0 or 1)
173  *
174  * attention status LED, so we use a callback that
175  * was registered with us.  This allows hardware specific
176  * ACPI implementations to blink the light for us.
177  */
178  static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
179  {
180 	int retval = -ENODEV;
181 
182 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot_name(hotplug_slot));
183 
184 	if (attention_info && try_module_get(attention_info->owner)) {
185 		retval = attention_info->set_attn(hotplug_slot, status);
186 		module_put(attention_info->owner);
187 	} else
188 		attention_info = NULL;
189 	return retval;
190  }
191 
192 
193 /**
194  * get_power_status - get power status of a slot
195  * @hotplug_slot: slot to get status
196  * @value: pointer to store status
197  *
198  * Some platforms may not implement _STA method properly.
199  * In that case, the value returned may not be reliable.
200  */
201 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
202 {
203 	struct slot *slot = hotplug_slot->private;
204 
205 	dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));
206 
207 	*value = acpiphp_get_power_status(slot->acpi_slot);
208 
209 	return 0;
210 }
211 
212 
213 /**
214  * get_attention_status - get attention LED status
215  * @hotplug_slot: slot to get status from
216  * @value: returns with value of attention LED
217  *
218  * ACPI doesn't have known method to determine the state
219  * of the attention status LED, so we use a callback that
220  * was registered with us.  This allows hardware specific
221  * ACPI implementations to determine its state.
222  */
223 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
224 {
225 	int retval = -EINVAL;
226 
227 	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot_name(hotplug_slot));
228 
229 	if (attention_info && try_module_get(attention_info->owner)) {
230 		retval = attention_info->get_attn(hotplug_slot, value);
231 		module_put(attention_info->owner);
232 	} else
233 		attention_info = NULL;
234 	return retval;
235 }
236 
237 
238 /**
239  * get_latch_status - get latch status of a slot
240  * @hotplug_slot: slot to get status
241  * @value: pointer to store status
242  *
243  * ACPI doesn't provide any formal means to access latch status.
244  * Instead, we fake latch status from _STA.
245  */
246 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
247 {
248 	struct slot *slot = hotplug_slot->private;
249 
250 	dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));
251 
252 	*value = acpiphp_get_latch_status(slot->acpi_slot);
253 
254 	return 0;
255 }
256 
257 
258 /**
259  * get_adapter_status - get adapter status of a slot
260  * @hotplug_slot: slot to get status
261  * @value: pointer to store status
262  *
263  * ACPI doesn't provide any formal means to access adapter status.
264  * Instead, we fake adapter status from _STA.
265  */
266 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
267 {
268 	struct slot *slot = hotplug_slot->private;
269 
270 	dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));
271 
272 	*value = acpiphp_get_adapter_status(slot->acpi_slot);
273 
274 	return 0;
275 }
276 
277 static int __init init_acpi(void)
278 {
279 	int retval;
280 
281 	/* initialize internal data structure etc. */
282 	retval = acpiphp_glue_init();
283 
284 	/* read initial number of slots */
285 	if (!retval) {
286 		num_slots = acpiphp_get_num_slots();
287 		if (num_slots == 0) {
288 			acpiphp_glue_exit();
289 			retval = -ENODEV;
290 		}
291 	}
292 
293 	return retval;
294 }
295 
296 /**
297  * release_slot - free up the memory used by a slot
298  * @hotplug_slot: slot to free
299  */
300 static void release_slot(struct hotplug_slot *hotplug_slot)
301 {
302 	struct slot *slot = hotplug_slot->private;
303 
304 	dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));
305 
306 	kfree(slot->hotplug_slot);
307 	kfree(slot);
308 }
309 
310 /* callback routine to initialize 'struct slot' for each slot */
311 int acpiphp_register_hotplug_slot(struct acpiphp_slot *acpiphp_slot)
312 {
313 	struct slot *slot;
314 	int retval = -ENOMEM;
315 	char name[SLOT_NAME_SIZE];
316 
317 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
318 	if (!slot)
319 		goto error;
320 
321 	slot->hotplug_slot = kzalloc(sizeof(*slot->hotplug_slot), GFP_KERNEL);
322 	if (!slot->hotplug_slot)
323 		goto error_slot;
324 
325 	slot->hotplug_slot->info = &slot->info;
326 
327 	slot->hotplug_slot->private = slot;
328 	slot->hotplug_slot->release = &release_slot;
329 	slot->hotplug_slot->ops = &acpi_hotplug_slot_ops;
330 
331 	slot->acpi_slot = acpiphp_slot;
332 	slot->hotplug_slot->info->power_status = acpiphp_get_power_status(slot->acpi_slot);
333 	slot->hotplug_slot->info->attention_status = 0;
334 	slot->hotplug_slot->info->latch_status = acpiphp_get_latch_status(slot->acpi_slot);
335 	slot->hotplug_slot->info->adapter_status = acpiphp_get_adapter_status(slot->acpi_slot);
336 	slot->hotplug_slot->info->max_bus_speed = PCI_SPEED_UNKNOWN;
337 	slot->hotplug_slot->info->cur_bus_speed = PCI_SPEED_UNKNOWN;
338 
339 	acpiphp_slot->slot = slot;
340 	snprintf(name, SLOT_NAME_SIZE, "%llu", slot->acpi_slot->sun);
341 
342 	retval = pci_hp_register(slot->hotplug_slot,
343 					acpiphp_slot->bridge->pci_bus,
344 					acpiphp_slot->device,
345 					name);
346 	if (retval == -EBUSY)
347 		goto error_hpslot;
348 	if (retval) {
349 		err("pci_hp_register failed with error %d\n", retval);
350 		goto error_hpslot;
351  	}
352 
353 	info("Slot [%s] registered\n", slot_name(slot));
354 
355 	return 0;
356 error_hpslot:
357 	kfree(slot->hotplug_slot);
358 error_slot:
359 	kfree(slot);
360 error:
361 	return retval;
362 }
363 
364 
365 void acpiphp_unregister_hotplug_slot(struct acpiphp_slot *acpiphp_slot)
366 {
367 	struct slot *slot = acpiphp_slot->slot;
368 	int retval = 0;
369 
370 	info("Slot [%s] unregistered\n", slot_name(slot));
371 
372 	retval = pci_hp_deregister(slot->hotplug_slot);
373 	if (retval)
374 		err("pci_hp_deregister failed with error %d\n", retval);
375 }
376 
377 
378 static int __init acpiphp_init(void)
379 {
380 	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
381 
382 	if (acpi_pci_disabled)
383 		return 0;
384 
385 	acpiphp_debug = debug;
386 
387 	/* read all the ACPI info from the system */
388 	return init_acpi();
389 }
390 
391 
392 static void __exit acpiphp_exit(void)
393 {
394 	if (acpi_pci_disabled)
395 		return;
396 
397 	/* deallocate internal data structures etc. */
398 	acpiphp_glue_exit();
399 }
400 
401 module_init(acpiphp_init);
402 module_exit(acpiphp_exit);
403